NickiNav is a Wakeboard / Wakesurf app that offers a GPS Speedometer, and adjusts your media volume based on speed.
With additional hardware, this app can even offer a full Speed Control Solution by varying throttle input similar to Perfect Pass.
No hardware required!
GPS Speedometer Display
Automated "Tow Timer"
Adaptive Volume Leveling
Lowers phone output volume as you slow down to pick up a fallen rider
Pitch and Roll Measurements (lay phone flat to view)
Play / Pause / Next / Previous track
Open Rider Playlist (interfaces with common media players)
For speed control, purchase a NICKiNAV Control Module:
Long press the Play/Pause Button to open Music App.
Long press the Timer text to Start / Reset it.
*SAMSUNG, HUAWEI AND ANY USERS HAVING ISSUES WITH APP NOT RUNNING WHILE SCREEN IS OFF: If you notice the app not changing volume while running in the background or with the screen off (but it works fine with the screen on) you're most likely in a power saving mode that is stopping apps from running in the background. To resolve this, simply go to your phone's Settings, search for Power Mode and ensure that you are in Optimized or High Performance mode selected. "Medium" and "Maximum" Power saving modes can stop the app from functioning.